Both Johnny Depp and Captain Jack Sparrow are Hollywood icons these days so it’s not necessarily that surprising that Brenton Thwaites would be nervous.
Brenton Thwaites is all of 27 years old, meaning he was around 13 when Pirates of the Caribbean: Curse of the Black Pearl debuted and introduced the world to Captain Jack Sparrow.
For what it’s worth he says that the scene in question is actually “one of the finer scenes” in the movie now, so he was apparently able to get over his nerves.
It’s unlikely the young boy in the movie theater had any idea he’d become part of the franchise 14 years later and find himself acting with the character on the screen.